'Bitter' in the Bible

The great day of the Lord is near, it is near and coming very quickly; the bitter day of the Lord is near, coming on more quickly than a man of war.

Even their silver and their gold will not be able to keep them safe in the day of the Lord's wrath; but all the land will be burned up in the fire of his bitter wrath: for he will put an end, even suddenly, to all who are living in the land.

My ears have been open to the bitter words of Moab and the words of shame of the children of Ammon, which they have said against my people, lifting themselves up against the limit of their land.

For this reason, go on waiting for me, says the Lord, till the day when I come up as a witness: for my purpose is to send for the nations and to get the kingdoms together, so that I may let loose on them my passion, even all my burning wrath: for all the earth will be burned up in the fire of my bitter passion.